(a) Upon every person engaging or continuing within this City in the business of producing for sale, profit or commercial use any natural resource products, the amount of such tax shall be equal to the value of the articles produced as shown by the gross proceeds derived from the sale thereof by the producer, except as hereinafter provided, multiplied by the respective rates as follows.
(b) Limestone or sandstone, quarried or mined, one-half of one percent (.5%); sand, gravel or other mineral product, not quarried or mined, one-half of one percent (.5%); timber, one half of one percent (.5%); coal, oil, natural gas, and other natural resource products, one-half of one percent (.5%). The measure of this tax is the value of the entire production in this City, regardless of the place of sale or the fact that delivery may be made to points outside the City. (1975 Code Sec. 10-68)